1. Field of the Invention
The present invention relates to an information distribution system such as a video-on-demand (VOD) system. More particularly, the present invention relates to a method and apparatus for providing scalable in-band and out-of-band communications channel support such that incremental increases in-bandwidth requirements are accommodated in a predictable manner.
2. Description of the Background Art
VOD systems providing content encoded according to the various Moving Pictures Experts Group (MPEG) standards are known. For example, a first standard known as MPEG-1 refers to ISO/IEC standards 11172, which is incorporated herein by reference in its entirety. A second standard known as MPEG-2 refers to ISO/IEC standards 13818, which is incorporated herein by reference in its entirety. Additionally, a compressed digital video system is described in the Advanced Television Systems Committee (ATSC) digital television standard document A/53, incorporated herein by reference.
Current video-on-demand systems typically rely on content distribution systems designed for broadcast services, in which programs are transmitted to all subscribers at once. These VOD systems typically broadcast programs such as popular movies at staggered time intervals or live sporting events at a single broadcast time. Thus, the bandwidth allocations to the "in-band" (video delivery and associated audio delivery) channels of the access system are substantially fixed, regardless of the amount of subscribers within the VOD system. Each subscriber simply selects or, more appropriately, elects to decode and present a broadcast information stream including a desired program.
Within such a VOD system, the addition of digital services (such as interactive entertainment or other services) requires careful analysis of all existing and proposed digital services which utilize the "out-of-band" channels of the access system, followed by a renegotiation of access system support among all the digital service providers. The resulting system configuration tends to be excessively large in terms of the equipment required to implement incremental increases in digital services. This increase in equipment size and cost is of particular concern within the context of the smaller cable network hubs presently being deployed by a number of cable television systems. Additionally, the complexity of such equipment tends to prohibit the remote location of the digital services support equipment.
Therefore, it is seen to be desirable to provide an efficient method and apparatus for incrementally increasing (or decreasing) bandwidth capacity supporting digital services provided to a population of subscribers or users within, illustratively, a cable television system. It is also seen to be desirable to provide a method and apparatus responsive to increases (or decreases) in either the number or type of digital services provided to the subscriber population and to increases (or decreases) in the size of the subscriber population utilizing such digital services.